Exodus 26:16-21

16Ten cubits shall be the length of a frame, and a cubit and a half the breadth of each frame.

17There shall be two tenons in each frame, for fitting together. So shall you do for all the frames of the tabernacle.

18You shall make the frames for the tabernacle: twenty frames for the south side;

19and forty bases of silver you shall make under the twenty frames, two bases under one frame for its two tenons, and two bases under the next frame for its two tenons;

20and for the second side of the tabernacle, on the north side twenty frames,

21and their forty bases of silver, two bases under one frame, and two bases under the next frame.